A wide variety of materials used in construction industries are packaged in buckets. A few examples of such materials are paint, deck stain, waterproofing compound, drywall joint compound, spackle, putty, thin set mortar, flooring adhesive, roof coating, and driveway sealant. The buckets typically have a cylindrical or frustoconical body and a detachable lid which fits on the upper end of the body and can seal the interior of the bucket in an airtight and watertight manner. The body is frequently equipped with a handle. The size of such buckets typically ranges from less than 1 gallon up to 7 gallons, with 5-gallon buckets being particularly common. The term “5-gallon bucket” is a nominal designation, and it is often used to refer to a bucket containing less than exactly 5 gallons, such as 4.5-5 gallons. The lid usually has a somewhat larger diameter than the lower end of the body to allow one bucket to be stacked atop another bucket with the bottom end of the upper bucket nested in the lid of the lower bucket. Namely, the lower end of the upper bucket rests atop the lid of the lower bucket without extending outside of the outer periphery of the lid of the lower bucket. When products packaged in these buckets are shipped from one location to another, such as from a factory to a warehouse or from a warehouse to a store, it is common to place the buckets in one or more layers atop a pallet, with each bucket touching or closely spaced from adjoining buckets in the same layer. The buckets are usually loaded onto or unloaded from a pallet one at a time by hand. Not only is the process of loading and unloading buckets with respect to a pallet time-consuming, it is very arduous work on account of the weight of the buckets (a five-gallon bucket of latex paint will typically weigh on the order of 50 pounds) and can result in back strains and other injuries to workers.
Devices referred to as layer pickers have been developed for lifting entire layers of items from a pallet. However, layer pickers generally require that the sides of the objects in the layers be vertical, so they are not suitable for lifting a layer of frustoconical objects such as many buckets. In addition, layer pickers are not capable of selectively lifting just a portion of the objects in a layer rather than the entire layer.
Devices for lifting 55-gallon barrels have also been developed. However, such devices are unable to access closely-spaced objects and are therefore unsuitable for handling buckets disposed on a pallet in a closely-spaced layer.
Accordingly, there is a need for an apparatus which can lift a portion of the buckets arranged in a closely-spaced layer.